热暴露对Ti750高温钛合金组织及性能的影响  

Effects of Thermal Exposure on Microstructure and Properties of High-temperature Ti750 Alloy

作　　者：朱川 姚俊卿 徐朗 樊自田[1] 王凯 杨力 龚小龙 刘鑫旺[1,3] Zhu Chuan;Yao Junqing;Xu Lang;Fan Zitian;Wang Kai;Yang Li;Gong Xiaolong;Liu Xinwang(State Key Laboratory of Materials Processing and Die&Mould Technology,School of Materials Science and Engineering,Huazhong University of Science and Technology;Hebei High-end Light Alloy Precision Forming Technology Innovation Center;Dekai Intelligent Casting Co.,Ltd.)

机构地区：[1]华中科技大学材料科学与工程学院材料成形与模具技术全国重点实验室 [2]河北省高端轻质合金精密成型技术创新中心 [3]河北钢研德凯科技有限公司

出　　处：《特种铸造及有色合金》2023年第12期1683-1687,共5页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(52271097)。

摘　　要：在750℃下对均匀化处理后Ti750合金分别进行了0、30和60 min的热暴露试验,研究了热暴露对其组织及性能的影响。结果表明,经均匀化处理后Ti750合金的显微组织为魏氏组织;热暴露过程中,在魏氏组织的β晶粒晶界处出现粗大片层的初生α相,晶界处α相和β晶粒内的细针状α集束尺寸长大,并有α2相(Ti3Al相)和硅化物析出,使得合金的室温脆性显著增大。在750℃下热暴露60 min后,合金的室温抗拉强度从1 080 MPa下降至1 004 MPa,降低了7%,且伸长率降为零。Ti750合金在高温环境中的微观组织演化和脆性相析出,会导致室温力学性能下降。Thermal exposure experiments were carried out on homogenized Ti750 alloy at 750℃for 0,30 min and 60 min,respectively,and the effect of thermal exposure on microstructure and properties was investigated.The results indicate that the microstructure of Ti750 alloy after homogenization treatment is Widmanstatten structure.During the thermal exposure process,coarse lamellar primaryαphase appears at the grain boundary ofβgrain of Widmanstatten structure,and the size of fine needle-likeαcluster inαandβgrains at the grain boundary grows,accompanied withα_2 phase(Ti_3Al)and silicide precipitate,leading to significant increase of brittleness at room temperature.After thermal exposure at 750℃for 60 min,the tensile strength is decreased from 1080 MPa to 1004 MPa,which is decreased by 7%,and the elongation is decreased to zero.Therefore,the mechanical properties of Ti750 alloy can be decreased due to microstructure evolution and brittle phase precipitation in high temperature environment.

关 键 词：热暴露 Ti750钛合金 微观组织 拉伸性能 热稳定性 

分 类 号：TG146.23[一般工业技术—材料科学与工程]